The seeds of plants rich in vegetable oil (oleaginous plants) are pressed to dissociated the oil form the solid plant matter. Currently, oils from rapeseed, sunflower, palm, soyabeans, jatropha and mustard, as well as residual vegetable oils are used for biodiesel production.
Biodiesel is a biofuel obtained from a chemical reaction between a vegetable oil and an alcohol (usually methanol or ethanol) in the presence of a catalysor such as potassium hydroxide (KOH) or sodium hydroxide (NaOH). During this process named transesterification, both biodiesel and glycerol are produced. The latter is separated from the biodiesel. The chemical name of biodiesel is fatty acid methyl (or ethyl) ester (FAME).
In 2006 in Germany, biodiesel is mainly used by utilitarian cars (about 50% of total sales), the percentage used for personal cars remains minor (6%). About 40% of the biodiesel are added to classical diesel and sold under the name B5, B10, B20 for diesel containing 5, 10 ou 20 % of biodiesel, respectively (source : FNR, Allemagne).
In France
In France, biodiesel is essentially produced from rapeseed and to a lower extent from sunflower seeds. The use of animal fat and used cooking oils is also considered (source: French Department for Ecologie, and sustainable Development, Department for Economy, Finances and Employment).
In France, the part of biodiesel compared to global energy consumption for transport is 0,7% in 2005 (source: Eurostat).
In Europe
Also in Europe, rapeseed remains the major plant resource intended for biodiesel production. Its productivity per hectare and per year reaches 1550 litres in 2008 (source : German Agency for Renewable Resources FNR). The productivity varies depending on the plant resource.
In Europe, the production of rapeseed and its oil has not been sufficient to cover the needs in biodiesel of the industry since 2005 (source: Oilworld).
From 2001 to 2007, the consumption of rapeseed oil in the European Union (EU) has doubled and exceeded 7,8 million tons, of which 64% have been used for biofuel production. It is noteworthy that rapeseed consumption in the food industry domain has decreased because of the increase in price since the end of the 90s.
Until today, the increase in vegatable oil consumption in Europe is principally covered by importing the following four oils (year 2007):
- palm oil (4,58 million tons),
- soyabean oil (0,62 million tons),
- rapeseed oil (0,48 million tons),
- sunflower oil (1,17 million tons) (source: Oilworld).
On a world scale
In 2006, France was the third biodiesel producer (0,63 billion litres) in the world after Germany (2,8 billion litres, more than 50% of the world production of biodiesel) and the United States (0,85 billion litres) (source : REN21 RE 2007 Global Status Report).
Other main producers of biodiesel in Europe are Austria, Belgium, the Czek Republic, Denmark and the United Kingdom (source : REN 21 RE2007 Global Status Report).
Biodiesel production rapidly increased on a worldwide scale with an annual mean increase of 40 % between 2002 and 2006, and more than 50% in 2007 (source : REN21 RE2007 Global Status Report).
A rapid expansion can be observed in Asia (Malaysia, Indonesia, Singapore, China), in Latin America (Argentine, Brazil) and in South Eastern Europe (Romania and Serbia). The ambition of Malaysia is to occupy 10% of the world market for biodiesel. In the context of a program on biofuels, Indonesia has planned to increase from 1,5 million hectares of cultivated oil palm tree to 7 millions in 2008 (source : REN 21 RE207 Global Status Report).
Positive aspects
- Biodiesel is a renewable energy that can contribute to a decreased use of fossil energy resources and decreased greenhouse gas emissions. The amount of CO2 emitted during biodiesel combustion equals the amount absorbed by the plants during photosynthesis.
- In order to reduce CO2 emissions, an EU directive of 2001 aims at a biofuel contribution of 5,75% of the total transport fuel in Europe for 2010 (source: EU directive 2001/77/EC). To reach this , several European countries put in place a system of tax exemption on biofuels and more particularly biodiesel, to increase their competitiveness. A remarkable increase of the percentage of biodiesel incorporated in diesel can be observed in Germany, France, Spain, and Italy. A more common approach between European countries would promote more efficient and econimical strategies. The current strategies however do illustrate the speed of evolution on the market.
- In Europe, unused arable land could be used for biodiesel production, with a potential for economical revival and job creation in rural regions.
- Compared to other resources for renewable energy, the costs of production are relatively low and the technologies currently on the market allow high scale production.
Negative aspects
- In 2008, in comparison with other biofuels - bioethanol, BtL (Biomass to Liquids), biogas - the yield (in l/ha y) of biodiesel remains low (source: FNR, Germany).
- Cultivation of plants for biodiesel requires arable land and is therefore in competition with cultivation of plants for the food industry. An increase in food prices and subsequent food crises can be feared. An increase in cultivation of plants for biodiesel can be observed in developing countries. Non-governmental organisations (ex: Friends of the Earth, Greenpeace, WWF) demand a development which is social, ecological and economically sustainable and which takes into account the evolution of food prices and accessibility, the ecological consequences such as the threat on biodiversity, CO2 emissions and pollution of the environment.
- The monoculture of plants for largescale biodiesel or bioethanol production can be a threat for biodiversity, and lead to increased deforestation and impoverishment of the soil. The use of fertilizers and pesticides add to the problems of soil and water pollution.
- The Ecobilan study launched in 2002 by the ADEME (French governmental agency for environment and energy management) and the DIREM (direction for energetic and mineral resources) suggests that greenhouse gas reduction, obtained by replacing diesel with biodiesel, remains low:
The numbers indicate a greenhouse gas reduction of about 4 % compared to conventionnal diesel for a mix of 95% diesel and 5% biodiesel (source: Ecobilan).
With the hypothesis of an incorporation of 100 % biodiesel, the outcome in greenhouse gas is about 3,5 times less than that of diesel. Consistent with this study, the German Federal Environment Agency pronounces that the reduction of CO2 emissions ranges from 20 to 80 % when pure biodiesel is used compared to pure fossil diesel. This large range results partially from the different possibilities for the use ofsecondary product use occuring during biodiesel production (straw, farming waste). Without the recycling of secondary products, the ecological and economical balance of biodiesel remains low.
Greenhouse gas emissions coming from field fertilization, in particular nitrous oxide (laughing gas), and the fossil resources used for farming (farm machinery, transportation, chemical prodcuts etc.) can shift the balance.
In order to reduce greenhouse gas emissions coming from transport, the cultivated surface should be strongly increased - According to the German Federal Environment Agency, this view is not realistic on a global scale because of the costs and the amount of arable land required.
Lines of reflection
- On the long term, the potential of each biofuel depends on its energy balance, its contribution to mitigating climate changes, the availability of the resources, its capacity of integration in existing facilities and the costs of production.
- The viability of long term investments are questionned since the outcome of the reduction of emissions is relatively low for biodiesel and the ecological impacts are high. Are biofuels real alternatives in terms of CO2 emission reduction and independence from fossil resources?
- Politicians agree with the public opinion to make biomass production a lasting and sustainable energy resource. To do so, the European Comission published a directive for renewable energies (Directive of the European Parliament and of the Council on the promotion of the use of energy from renewable sources, 2008). The set up of a sustainable production capacity should become a fundamental condition to obtain financing and subsidies (source: European Comission).
Perspectives
- Biodiesel can currently replace a low but significant part of the fossil resources. Its development contributes to the protection of the climate.
In a near future, it is hoped that farm land will be used more efficiently for biofuel production. Greenhouse gases associated to biodiesel production should be reduced even more to reach a more positive global balance. Current technology developments on second generation biofuels should also push forward a more sustainable biodiesel production.
References
German Federal Environment Agency UBA
German Agency for Renewable Ressources FNR
Global Warming Potentials UNFCCC
DGEMP French General Management of Energy and Climate- Files on biomass (in French)
UN - report on renewable energies
FORRES 2020: Analysis of the renewable energy sources’ evolution up to 2020
REN 21 RE2007 Global Status Report
SEFI Investment Report 2007
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